Effect of ultrahigh-pressure treatment on the volatile components and chemical composition of sea buckthorn (Hippophae rhamnoides) pulp: Prediction of biochemical pathways for the formation of aroma compounds

• UHP mainly affected the fruity, floral and green aroma of SBP. • UHP reduced the free amino acid and organic acid content and increased the free fatty acid content. • Compounds such as 1-octen-3-ol, dimethyl sulfide, and glucose were the differentiated substances in SBP treated with UHP. • Mechanisms of formation and transformation of potential aromatic components in SBP were hypothesized. The effects of ultrahigh-pressure (UHP) treatment on volatile and metabolic compounds in sea buckthorn pulp (SBP) were investigated. The results showed that UHP treatment mainly affected the contents of esters, alcohols and aldehydes in SBP, thus affecting fruit, floral and grassy aromas. UHP treatment significantly decreased the free amino acid and organic acid contents and increased the free fatty acid content in SBP. Partial least squares discriminant analysis (PLS-DA) revealed 13 differential volatile compounds and 24 differential metabolic compounds in SBP under different UHP conditions. Formation pathway analysis of aroma components revealed several pathways that may underlie variations in the aroma of SBP, including oleic metabolism, linoleic acid metabolism, phenylalanine metabolism, limonene metabolism, glycolysis, linolenic acid metabolism, the citrate cycle, isoleucine metabolism, and methionine metabolism.